Automatic punching press



May 22, 1928.

1,670,648 0. S. BEYER AUTOMATIC PUNCHING PRESS Filed Aug. 12, 1925 5 Sheets-Sheet 1 INVENTOR 6 M) L26! 6r".- I T r 8 By Attorneys;

May 22, 1928. 1,670,648

0. S. BEYER AUTOMATIC PUNCHING PRES S Filed Aug- 1925 5 Sheets-Sheet 2 J "mm INVENTOR Bu Attorneys,

\ aha/am W WJ 2s May 22, 1928.

O. S. BEYER AUTOMATIC PUNCHING PRESS Filed Aug. 19, 1925 5 Sheets-Sheet 3 INVENTOR @2 3 :4 2' By Attorneys, m M M May 22, 1928. 1,670,648

0. s. BEYER AUTOMATIC PUNCHING PRESS Filed Aug. 19, 1925 5 Sheets-Sheet By Attorneys, am

May 22, 1928.

1,670,648 0. S. BEYER AUTOMATIC PUNCHING PRESS Filed Aug. 19, 1925 5 Sheets-Sheet 5 Fig 1.5.

INVENT OR By Attorneys, WM) d% la -a a chines cannot-be Speed Patented May 22, 1928.

UNITED- STATES PATENT OFFICE.

one a. arms, or aaooxmm, new

YORK, ASSIGNOB, BY rm ABSIGHIERTS. TO

2. W. was columns, or aaooxnvx, new max, a concurrent or nmwaim I anroau'rrc runcxnm ems a uuuu and August :9, 1m. lea-lahlo. 11.1.

This invention relates to presses for punching a circular series of holes or slots In a plate. Such punched plates are commonly the laminated cores the armat'utes or field magnets of dynamo electric machines. The laminae for such cores require to be punched with great accuracy, so that when superposed their holes or slots will precisely coincide. Two ways of punching to such lamina: have been practiced: (1) Accordi 'to the first method, a air of multip e dies is made for the simu taneous punching at one'stroke of all the holes or slots of the circular series required to make la the complete punching: but especially in the case of laminae having numerous holes or slots, such dies are extremely ex 'sive, so that this method is usually pro ibitive in cost. (2) The second method is to provide no asingle pair of dies adapted for punching one hole or slot at a tiine, and to provide the punching press with an automatic feed whereby the work carrier is turned ate step after 'each punching. until the entire ll circular series (or fraction thereof) is com pleted, whereupon the automatic feed sto the machine and the operator takes out a work. It is'to the latter clam that the present invention pertains. so The punching of ore laminte in this manner is comparatively slow, especially in the case of those having numerous holes or slots to the complete circumference, since usually even the most rapid of such ma-' p e up above 200 strokes per minute. It results that the cost of production in this 'way is much greater than the cost by the first method after the first cost of the multiple dies has been met.

40 Consequently. when the lamina are to be produced inzu'at quantities. it is more economical to incur the heavy expense for such dies, so that the complete-'lmuinu may he struck out at one stroke. The present invention aims to provide on automatic press witha single punch and die which would be capable of operating at such speed as to produce the punched sheets or laminae, with a rapidity comparable to that obtained with the complete pair of dies.

Every such press requires. when manually started. to operate through a given cycle or succession of punching strokes until the work is completed, and then to automatically stop with 'great precision. To accomproximately 400 or 600 strok consistent with strength,

parts of the machine have plish this requires that its main shaft be driven from a suitable drivin member through a positively acting clutc so as to insure that'the stopping of the machine shall occur with great precision upon the completion of the series of punchings, and with the punch elevated and the automatic feed at rest. .It has been found in practice that such clutches cannot be controlled at a higher shaft speed than about 200 R. P. M. It follows that with presses as ordinarily constructed the extreme punching speed is approximately 200 strokes per minute.

he present invention seeks to multi ly the product of such presses b the )unching speed above the imitin speed of clutch control. Assuming that such limiting speed is 200 R. P. M., the present invention results in doubling or preferably trebling that speed so as to give the punch apes per minute. Phis is accomplished by driving the shaft at a' s closeto the limit of such clutch contro and driving a punch therefrom through accelerating means such as n multiple cam or equivalently by being geared up to a crank or eccentric driving the punch.

The invention further rovides means for imparting an accelerated feed, so that the feeding of the sheet or plate is speeded up to the same. extent as the unching operation. Tothis end the carririr for the work is given a rapid succession of forward feeding' movements-which are multiplied beyond the speed of the main or driving shaft in the same ratio as the multiplication of the punch movements.

To attain movements at such high speeds, provision is made for eliminating as far as possible all reciprocating movements and utilizing rotary movements [to the utmost extent. in practice the machine embodying this invention has no reciprocating parts which come into function in the operation of punching the work, except the head cnrrymg the punch itself. It is not considered feasible to operate a punch otherwise than rectilinear movement, and for this reason a reciprocating punching head' is required; but it is made of the minimum mass so as to be capable of extremely rapid reciprocation. All'other solely rotary movements, and all except the wor carrier have continuous rotation at uniform speed.

multiplying The work carrier necessarily comes to a complete rest before each punching stroke, its feeding movement including agradual acceleration to the maximum, and'then an equally gradual retardation ending in the next succeeding dwell.

The invention further provides an improved type of feeding mechanism for ac coinplislnng these desirable movements of the work carrier. This feeding mechanism is of the Geneva cross type, its driving and driven members being in constant engagement so as to afford a positive motion.

As the feed movement requires more time than the punching, it is desirable to provide that the punch, which has a short stroke, shall be in engagement with the late being punched for not over about onet llld of the total time for each punching stroke. thereby leaving aiproximately two-thirds of such time for the feeding of the work into 0si tion for the next stroke. During this eeding period the punch is ascending above the work to a convenient distance, and descending into contact with the work to be punched at the next stroke.

Having now indicated the general nature of the invention and of the automatic punching machine embodying it. I will roceed to describe in detail the preferred eui odiments of the invention with reference to the accompanying drawings. wherein- Fig. 1 is a. side elevation of the machine.

Fig. 2 is a front ele ation thereof lpartly in vertical section, on the line "2-2 in ig 4.

Fig. 3 is a rear elevation, the main siaft being in section on the line 3-3 in Fig. 1.

Fig. 4 is a plan of the machine. the work carrier being removed and its driving gear being partly broken away.

Figs. 5 and 6 are enlarged details pf the punch driving means, Fig. 5 being aitransverse section in the plane of the line -5 in Fig. l, and Fig. (i a longitudinal section in the plane of the line (3-6 in Fig. 5.

Fig. 7 is a transverse section on the same plane as Fig. 2. but on a larger scale.

Fig. 8 is a horizontal section on the line 8-44 in Fig. 7. showing the Geneva cross feed dn'ving device.

Fig. 9 is a similar view showing another construction of the feed driving movement.

Fig. 10 is a fragmentary elevation on a larger scale. of the clutch element shown in section at the right in Fig. 1. Fig. 11 is a view from underneath in Fig. 10. of the clutch bolt 8 and unlocking dog r.

Fi 12 is a transverse section of the driving graft, showing the clutch dogs out of action and the clutch bolt engaged.

Fig. 13 is a plan showing two different types of punchings such as this press is capable of producing. having respectively internal and external notchings.

Fig. 1-1 is a. side elevation corresponding to Fig. 1, showing a somewhat different const ruction of press, certain parts being in vcrtical mid-section.

Fig. 15 is a front elevation of the press shown in Fig. 14, the view corresponding to Fig. 2. and certain portions being in vertical section in the same plane as in Fig. 2.

Fig. 16 is a plan of the feed table of Figs. 14 and 15 showing its mounting.

Referring first to the embodiment shown in Figs. 1 to 12, the general construction of the machine. so far as concerns its framework and driving means, and the means for starting and stopping the feed, is in general similar to that common with other such machines. The frame A of the machine constitutes a pillar rising from the base, supporting the punching head A and having at a convenient level a horizontal projection A for carrying the feeding means. The upper part of the frame provides bearings for the main shaft B which is driven from a driving wheel C which may be a belt pulley orany other rotary member suitably driven from the motor means. which may be an electric motor. as shown in Fig. 1-1. It will in this description be assumed that the shaft B turns at 200 R. P. 31.. and that the punching rate is trebled, giving 600 punching strokes per minute. The shaft B carries on its front end a cam D having a working face of the sha e shown in Fig. 5, so as to force downwar the roller E three times to each revolution. Theroller E is carried by the punch slide F, which in any .usual way carries the punch G. The punch slide is lifted by a spring H seated on the top of the frame and pressing upwardly against a crosshead a which th ough tie-rods b b connects to the slide. give an easy risirfgl and falling movement similar to that which would be imparted by a crank geared. up to three times the speed of the shaft B. The sprin has such stitfness and resiliency that it'll ts the punch slide quickly after each depression and keeps the roller E always in firm contact with the cam D. By this means the punch is given three strokes to each turn of the main shaft B. The mass of the reciprocating parts kept down to the minimum con istent with adequate strength. so that the punch can rc-' ciprocate with great rapidity.

The plate or lamina to he punched. indicated at .r. is cnlllctl on a work carrier or turntable H of any usual or suitable construction. and which is shown in Fig. 1 as consisting of a disk having any ordinary means for fastening the work to it. It is mounted on a central shaft H and intermittently by the feed mechanism which will now be described.

This feed mechanism is driven in any suitable way from the source of power, and preferably from the main shaft B, so as to be e cam is conformed to is rotated timed in perfect synchronism with the punch. In the construction shown, the shaft B drives through bevel gears the shaft I which extends down to and drives through bevel gears a shaft J, the latter extending horizontally and parallel to the shaft B, and havin bearings m the frame extension A. The s aft J may turn at the same speed as the shaft B, although it is preferable to speed it up somewhat through the intermediate bevel gears. The shaft J carries a gear 0 which may be a screw or worm gear. and which meshes with and drlves a pinion (I (see Fig. 7) which as shown as turning on a.

vertical axis, and which in turn through a cam action drives an intermittent rotor e. The gearing ratios are such that the pinion d makesone turn to each uneh stroke and each feed movement. whic in the example assumed is 600 R. P. M. The rotor c is fiexed on a spindle e on the upper end of which is detachably fitted a driving pinion f which meshes with and drives a large gear 9 which is detachably fastened to the shaft H and drives the carrier or turntable H. The cam driving connection between the pinion d and rotor e is such that to each rotation of the pinion the rotor is turned durin approximately two-thirds of the time and held stat'onary during the remaining time. The rotor may be var ously proportioned so as to be turned a given fraction of its revolution to each rotatiotiiof the inion; in the construction shown, which wil be described hereinafter, it is given one-sixth of a turn to each turn of the. inion. The parts are so co-related to.the uneh drive that the punch enters the metal plate and rises out of it durin a proximaely one-third of the time whl e t e rotor stationary; and while the unch is up clear of the work the rotor is given itsnext'forward movement, which advances the turntable far enough enough to feed the work the required distance for the next punching.- The precise extent of feed is determined by the ratio between the pinion'f and gear 9; and as these are removable and may be replaced by others of difl'ercnt' ratio, the extent of feed may he varied for each dilfcrcnt kind of work to be punched. without other" alteration of the machine than the substitution of these gears. i

Inasmuch as such change in gear ratio will commonly retuire setting the axes of the spindle e" an the turntable H at different distances apart, and as the punching of different diameters of work requires setting the axis of the turntable at varying distances from the uneh axis; it becomes necessary to provide or adjusting these relative dimensions. To this end the frame extensionA is formed as a slideway on which are mounted slides K and L. the former carrving the axil mounting of the turntable and the Avith a slit'leway .and turntable H are latter the bearing for the spindle c. As a matter of construction it is preferable to mount the slide K to slide on the frame extension and to provide it on its upper side on which the slide L moves. The slide K is moved by an adjusting screw K, and the slide l, is moved by an adjusting screw L. the former being turned'directly by a hand wheel and. crank k. and the latter by a hand wheel and crank I, through intermcdiate pinions 1/: shown in Fig. 4. The slide L carries not only the bearing for the spindle e, but also the hearing for the journal ll of the pinion (I, and also engages and locates the screw gear c which is splined upon the shaft J so as to slide upon it as the slide L is moved. The slide L is constructed as a hollow chamber enclosing the gears c. d. and rotor e, and forming a lubricating box therefor.

The means for starting and etc ping the machine will now be described. his consists of an ordinary and well-known form of positively-acting clutch or coupling which may be substituted by any other known construction which will accomplish the'same result. Since with the described proportions the machine makes three effective strokes to each turn of the main shaft, it is neces-.

sary that the driving clutch be constructed to stop the main shaft at any third of a turn (instead of at the end of a complete turn, as is usual in clutch-driven presses). Aside from this feature the construction of the clutch is not changed as compared with anv suitable type of'positive lock clutch; Well known clutches of. this type are the Blissconsolidated and the "Johnson clutch. The particular clutch shown in the drawings is of the Johnson'type. The hub of the driving-pulle C turns freely on the main shaft B until oeked to it by the clutch. The locking member is a bolt p seated in a collar or flange on the shaft B and impelled outwardly by a spring q to tause its-end to enter a recess in the hub C. When at rest the bolt p is field back by any one of three sto levers 1', each ofwvliieh has a tapering n as shown in Fig. 11. and enters a notch in the bolt behind a stud" a, a stop shoulder r on the stop lever r abutting against this part of the bolt to stop the shaft at a precise point, To start the press the three stop levers are thrown outward to the position shown in Fig. 12, whereby the one lever' hol the bolt releases it and the bolt is presse outwardly and enters the recess p on the revolving hub when the. latter arrives in coincidence with the bolt. The machine is thus started with precision at this exact point. When the required number of punch strokes have been performed, the machine is stopped by simultaneously throwing nward the three stop levers r, whereupon the one which is first encountered by the luJ III

holt p is engaged by the projecting lug s thereon. so that the inclined end portion of the stop lever pushes back this lug and therebv withdraws the bolt, and upon the lug striking the face r' the shaft is stopped with precision. The three stop levers.r are located at circumferential distances apart, so that the respectivelv stop the shaft at equal thir s of a complete revolution. For operating the stop levers r an oscillatory collar t is provided having any suitable operative engagement with the stop levers, as by pins u engaging oblique slots in the levers, so that the turnin of the collar t in one directioii throws t e levers simultaneously inward, and its turnin in the other direction throws them outwar The collar t is o erated by rods 11, 10 extending to a treadle ever T in a well known manner, so that b de ressin the treadle the rods are puller an the co lar is turned to throw out the rocking levers and thereby start the press. A spring S is suitably located to throw back the collar to the clutch releasing position; this is prevented by a springpressed catdh hook y engaging the rod 1: (or other suitable sto so that the stop levers are held inactive w ile the ress is rlunning through the prescribed punc ing eye e.

It is necessary to stop the press automatically at the precise point in the rotation of the turntable when the last punching has been made to complete the circular series of punehings required for the work. For this purpose an adjustable cam device is provided which acts to withdraw the hook y and permit the spring S to throw the three.

stop levers inwardly so as to withdraw and arrest the bolt at the coinciding third of a turn of the shaft. For this pur ose 21 Ste cam disk M is rovided, attac ed in a jnstable fixed re ation to the turntable H and gear g (see Fig. 1). This carries a tooth 21 which in its rotation encounters a pin 22 or other projecti n on an arm 23 which is pressed it by av spring 24. The a: m 23 has a spline connection with a shaft N which extends nrallel with the movement of the slides and carries the hook y. The pl' -ssing down of the pin 22 by the cam tooth J1 r cks th shaft N and withdraws the hook I so as to free the rod 2; and permit the. collar t to turn and throw the stop lovers 1- inwardly. By precisely adjusting the disk M to the proper position with respect to the turntable, it acts to thus stop the press at the instant when the last punching stroke has been performed.

Such stoppage of the machine must occur when the punch is elevated out of the work. It should occur when the punch stops at the upper end of its stroke in order to avoid the jar of stopping the punch (which is the only reciprocating part of any weight) dura collar 2 on iug its stroke. This, however, involves stopping the feed at mid-movement. A compromise may be made by stop mg the punch on its up-stroke just as it c ears the work and before the movement of the turntable be ins.

he improved Geneva stop movement or device for giving the described feed motions will now be explained.

Referring particularly to Figs. 7 and 8, the rotor (l carries an eccentrically-mounted pin or cranlt stud 31, and is formed with a concentric sector 32 which is cut away on the side toward the stud. The driven rotor e is formed with a series of radial grooves or slots 33, shown in Fig. 8 as being six in number; it is also formed between these with recesses 34 having arc-shaped faces of like radius to the sector 32. The central portion of the rotor e is so far cut away that the stud 31 in its rotation may swing from one radial slot 33 to the next; in Fi 8 the entire central portion is cut away, orming a chamber 35. In Fig. 8, where the rotor d is turning in the direction of the arrow, its stud 31 is just entering one of the radial slots 33, and its sector 32 is beginning to pass out of engagement with the corresponding concave wall of the arc-shaped recess; from this point the stud in its orbital niovement carries the driven rotor with it by its engagement with the walls of the slot 33: this movement begins imperceptibly and gradually increases in velocity until the stud is at its point of greatest distance from the axis of the driven rotor, and from this point the movement imparted to the latter gradually slows down until it stops just as the stud is emerging from the radial lnt in its next position. During this movement the sector 32 is swinging into the central chamber 35 and passes out of engagenn-nt with the recess 34 which it has been engaging and enters into engagement with the next recess 34, so that upon the completion of the movement it has so far engaged the latter as to hold-the driven rotor stationary, and it continuesso to hold it whil the tlltl is swinging from the slot 33 it has just left, to the next slot 33. This device is very simple and operates with great accurm-y. and imparts an ideal movement to the work carrier or holder H through the intermediate gearing; that is to say. the carrier starts very slowly from its position of rest. gradually accelerates to the middle oi its movement, and then. gradually retards until it finally oomes to rest again; and these movements occupy approximately two-thirds of one rotation of the driving rotor, the remaining third, while the stud 31 is out of action, being the rest period of the driven rotor, while the sector 32 is engaging the are face of one of its recesses 34.

The modified construction shown in Fig.

tlfi

loo

llU

. radial slots 9 has a somdw'hat different movement. The

driving rotoir. d has two studs 41 and 42, and a sccto'43; 'the driven rotor e has coifresponding to the slots 33 m Fig. 8, bpt closed inwardly and opening outwardly. The operation is thcsamc as that of an ordinary (icncva stop moven'iz-nt,

except that becanse'of the duplication of the feeding movement, which coincides with the topmost position of the punch slide; so that adapted for the.

by stopping the machine at 'thcqend of the cycle of punchin s at this instant it'is stop- Zped while both the principal moving parts are'at rest..

It'will be understood by those skilled in the'ar't that the machine may be variously modified according to the particular result.

in' anycase to be attained. It is assumed that the blank carrier has some. suitable means for clamping the blank-to it. These means will vary according to whether the blank is a disk or ring, and according to whether the punchings are at the outcr part or inner part. Fig. 13 shows two examples of the punching or lamina. at, theone on the left being a ring punched on. its inner mar gin, and the one on the right being a disk! punched on its outer margin. Numerous otherl kinds of punching. may be "rude, according to circumstances. .Th'e. blank carrier ofcourse will have. any suitable means for clamping the blank to it. b'utsueh means, being well knownin the art, are not illus trated. p

The. work carrier shown in F ig. 1 is v exteriorpunching of a disk or ring. For interim punching of a ring a somewhat. different design ofmachine is required, aln example of which is shown in Fig. 14, which is a view corresponding generally '0 Fig. 1. The mechanism here shown. is essentially the same as that, already described, ;except that the feed motion is communicated through skew gearing instead of bevel g earing. The blank carrier H is a ring centered by rollers 10' and havin exterior gear teeth driven by a. pinion which corresponds tothe pinion in Fig. 1. This construction permits the punch to descend inside of the blank carrier H, as shown. The mechanism illustrated in Fig. 15 requires no special description, except to state that the automatic stop means is actuated by a cam or button mounted adjustably on the blank carrier H and operating to lift the lever 123, the arm 1241 of which takes the place of the hook y in the previous construction, and by this movement is pulled out of engagement with the collar 2 on the rod '0' for stopping the machine. To adaptthe machine to annular blankholders H of varying internal radii, the rollers 10' are made adjustable in tangential or other suitable slots 10 as shown in Fig. 16.

In both constructions the treadle T con- 'nects through rod 10 with two rods u and 'u',

the former operating the clutch as already described, and the latter operating in usual manner the brake U for stopping the driving shaft without shock just as the clutch is released.

It will be understood that the details of the mechanism may be greatly varied without departing from the: underlying principles inherent in this invention.

J The invention is not limited to punching acircular disk or ring, nor to punching entirely around a circle, as the punching may be done upon an arc-shaped blank or blank of other form, and for any required number of punch strokes.

What I claim is: Y

.1. A- punching press having a clutch drive comprising a main aft, :1 positiveclutch having a plurality of release stops" spaced apart at equal angulaninten vals, means .for driving the shaft-through said clutch, whereby the shaft may be driven at aspeed within the limiting speed of clutch control, a plying punch-drivin transmission adapted to positive impel the punch duri n'g each punching stroke, said transmission multiplying-the punch speed by a ratio e ual to the number of clutch release stops, w ereby the shaft may be driven at aspecd within the limiting speed of clutch control, while the punch is accelerated to a multipleof such speed, and the press may-be stopped after any punching stroke.

2. A punching press according to claim 1, the punch driving trapsmission comprising'a cam having a plurality of projections for positively forcing the punch downward with a'frcqueney exceeding the speed of the?" feed motion synchronized with the punch ositive punch, and a speed-multimovements, having an accelerating and retardingfced movement adapted toimpart a. dwell to the blank being fed, whereby to hold the blank stationary while the punch is engaging the blank.

4. In a punching press having a main shaft and a punch with multiplying transmission for giving a plurality of punch strokes to each turn of said shaft, a mechanism for imparting a step-by-step feed mo tion comprising a driving rotor making one turn to each spunching stroke and a drivening the mg a driving member. and a (h-neva crosss'top device adapted to impart to the blank a gradual acceleration and retardation, adapted to accomplish a complete feeding movementin approximately two-thirds of the rotation of the driving member, and dwellmeans for driving the ing during the remaining third to permit the punch to enter and clear the. blank 6. A punching press including a driving shaft, a reciprocating punch, multiilying unch at a night-r speed than the shaft, a lank-carrier, with a mechanism for imparting a step-by-step feed motion to said carrier comprising a.

drivin rotor having a geared-up connection with t re driving shaft and makm one turn to each punching movement, an a driven rotor geared to the blank-carrier to advance the latter one space between punhings to each punching movement, said dri ng rotor having a cam-stud and stop-sector, and said driven rotor having radial slots engaged successively by said stud to impart such feeding movements, and arcs engaged by said sector to hold it stationary between the feedin movements.

l. A press according to claim 6, the feed motion (proportioned toadvance the blank carrier u driving rotor and to hold the blank carrier stationary for the punch' stroke during less than a half turn of an driving rotor.

8. .-\.step-by-step feed motion com rising *1: Geneva cross stop device with a riving rotor making one turn to each complete feeding movement, said driving rotor having a cam stud and a stop sector, a driven rotor having radial slots engaged successively by said stud, and an inner space wherein the stud may freely pass from one slot to another while the driven rotor is at rest, and reciprocal means for holding the driven tor stationary between the feeding movements, and a blank carrier geared to and dri've ht b the driven rotor.

9. A eed motion according to claim 6, the driving rotor having a cam stud and a stop sector, and the driven rotor having radial slots engaged by said stud, and internal ar -s engaged by said sector, the axis of the drivring more than a half turn of its plying means for driving the punch therefrom at higher velocity, u feed-mechanism for feeding the blank, and multiplying gearing driving such feed-mechanism in synehronism with the unch movements.

ll. high speet punching press having a positive clutch drive and a main shaft adapted to be driven at a speed approximating the limiting speed of clutch control, multiplyin" means for driving the punch at. a speed which is a multiple of the driving shaft speed, and multiple means for disengaging the clutch a'nd stoppin the shaft operable after any punching stro e.

12. A piess-aceording to claim 10. having means for unclntching and stopping the main shaft after any punch stroke, and automatic means in connection with the feed motion for determining, such stoppa at the end of a prescribed cycle of punc ing.

13. A high speed punching press havin multiplying means between the main aha and the punch for imparting to the punch multiple punching strokes to each turn of the shaft, a itive motion clutch for driving said shai z and multiple means for die engaging said clutch and stopping the shaft, ada ted to stop the shaft after any punching stro e.

14. 11' a high speed punching press, a main sh ft, a pane and intervening mechanism imparting to the punch three punc 11g strokes to each turn of the shaft a pos ti e motion clutch for driving said shaft, and triple releasing means for said clutch operable to disengage the clutch after any punching stroke.

15. A high speed punching press comprising a main shaft, multiplying means for driving the punch therefrom, a positive drive clutch, multiple clutch-releasin means adapted to disengage the clutch a or any punching stroke, and automatic means for simultaneously operating said clutch-releasing means whereby when they are brought into engagement the one nearest in the path of the clutch acts to stop the machine.

In nitness whereof, I have hereunto signed my name.

OTTO S. BEYER. 

